package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {

        //1.获取当前用户id
        Long id = UserHolder.getUser().getId();
        String key = "follows" + id;
        //2.根据isFollow判断是关注还是取消关注
        if (isFollow) {
            //关注
            Follow follow = new Follow();
            follow.setFollowUserId(followUserId);
            follow.setUserId(id);
            boolean isSuccess = save(follow);
            if (isSuccess) {
                //把关注的用户写入redis
                stringRedisTemplate.opsForSet().add(key, followUserId.toString());
            }
        } else {
            //取消关注
            boolean remove = remove(new QueryWrapper<Follow>().eq("user_id", id).eq("follow_user_id", followUserId));
            if (remove) {
                //删除redis关注的用户
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }
        return Result.ok();
    }


    @Override
    public Result common(Long id) {
        //1.获取你自己
        Long userId = UserHolder.getUser().getId();
        String key = "follows" + userId;
        //2.获取你查看的用户
        String key2 = "follows" + id;
        //3.取交集
        Set<String> set = stringRedisTemplate.opsForSet().intersect(key, key2);
        if (set == null || set.isEmpty()) {
            return Result.ok();
        }
        //4.获取共同关注的用户id
        List<Long> list = set.stream().map(Long::valueOf).collect(Collectors.toList());
        List<User> users = userService.listByIds(list);
        List<UserDTO> userDTOS = users.stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());

        return Result.ok(userDTOS);
    }





    @Override
    public Result isFollow(Long followUserId) {
        //1.获取当前用户
        Long id = UserHolder.getUser().getId();
        //2.去数据库里面查询是否有这条数据
        Integer count = query().eq("user_id", id).eq("follow_user_id", followUserId).count();
        return Result.ok(count>0);
    }
}
